Male Reproduction

scrotum

protects and supports the testes

regulates temperature (thermoregulation)

scrotum is comprised of

scrotal skin

tunica dartos (pushes testes up)

scrotal fascia

parietal tunica vaginalis (heat exchange)

scrotal skin

LOTS of sweat glands and nerve endings; very important for temp regulation

tunica dartos

smooth muscle layer that can contract or relax to adjust how close the testes are to the abdomen

scrotal fascia

muscle that helps to tighten and expand the scrotal skin

parietal tunica vaginalis

membrane pouch

thermoregulation of the testes

two methods of regulating temp by the scrotum

1. radiator = sweating

2. thermosensor

like a swamp cooler (i.e. evaporative cooling)

Testis (testes)

primary reproductive organ in the male

testes functions

producing spermatozoa, hormones, additional fluid

testicular capsule

visceral vaginal tunic

tunica albuginea- white connective tissue

parenchyma

major mass of the testis

seminiferous tubules

apart of the tubular compartment

parts of the interstitial compartment

leydig cells, blood vessels, lymphphatic vessels, connective tissue

components of the tubular compartment

pertibular cells, basement membrane, seminiferous epithelium, vasal compartment, tight junctions, adluminal compartment

seminiferous epithelium

Sertoli cells

• sometimes referred to as “nurse cells”

• produces estrogen

tight junctions

blood testis barrier; protects developing “foreign” germ cells

Blood-Testis Barrier (BTB)

created by basement membrane and tight junctions

Blood-Follicle Barrier (BFB)

found between theca interns and granulose cells of the follicle

basement membrane

the tubular and interstitial compartment are all housed in _____

lobules

rete tubules

join seminiferous tubules together to allow stern transport

mediastinum

central connective tissue and core of the testis

epidermis

seminiferous tubules —> rete tubules —> mediastinum —> efferent ducts —> epididymis

epididymis

1 duct

very long (30-60 meters)

maturation environment for spermatozoa

storage site/reservoir of sperm

three portions of the epididymis

caput: proximal end (top)

corpus: intermediate portion (middle)

cauda: distal end (farthest away)

number of sperm found within the epididymis is dependent on several factors

frequency of ejaculation

age

environmental effects (such as temp)

size of testes

sperm moving through the epididymis in bulls

10-14 days

sperm moving through the epididymis in rams

12-15 days

sperm moving through the epididymis in boars

~10 days

sperm moving through the epididymis in dogs

10 days

vas deferens/ductus deferens

main tube section of the make reproductive system

• everything from caudal epididymis —> urethra

passageway for spermatozoa

vasectomy

spermatic cord

suspends testis

extends through inguinal ring

• passage site of inguinal canal/junction between body cavity and testis

contains:

• ductus deferens/vas deferens

• cremaster muscle: “pushes” testes up towards the body

• vasculature, lymphatics, and nerves: pempiniform plexus

pampiniform plexus

countercurrent heat exchange system

pulse pressure eliminator

accessory sex glands

secretions produced by the epididymis and accessory sex glands produce a non-cellular liquid known as the seminal plasma (seminal plasma + sperm = semen)

ampulla, vesicular glands, prostate gland, bulbourethral glands/cowper’s glands

ampulla

enlargement of the ductus deferens that produce a lot of mucous

does have ampulla: bull, stallion, ram

vesicular glands

also known/called seminal vesibles

paired glands that contribute fluid to ejaculate

does have vesicular glands: bull, boar, stallion, ram

prostate gland

promotes sperm environment w/ pre-ejaculate

does have prostate gland: bull, boar, dog, tom, stallion

bulbourethral glands/cowper’s gland

produces a gel fraction to cause the seminal plasma to coagulate after ejaculation (prevents back flow of sperm)

does have: bull, ram, stallion, boar, tom

Penis

copulatory organ of the male

base of penis

attaches to ischial arch

shaft of penis

main portion of penis

glans penis

specialized/species specific end

lots of nerve endings

analogous to the clitoris in the female

erection of the penis

caused form the engorgement of blood into spongy erectile tissue

corpus cavernous and corpus spongiosum

erection and protrusion of the penis and ejaculation process are ________

under muscular control

ischiocavernous muscles

located at the base of the penis

limits blood flow away from the penis during an erection

urethralis

assists in moving seminal plasma and spermatozoa into the urethra

bulbospongiosus muscles

empties the extra pelvic portion of the urethra

sigmoid flexure

sigmoid flexure is maintained by the retractor penis muscles

this is present in species that have a fibroelastic penis and minimal erectile tissue (bulls, boars, rams)

“s” in sigmoid = “s like” figure